The present invention relates generally to a package labeling system, and more particularly, to a method and apparatus for transferring labels from a label source to a label applier such that the angular orientation of labels applied to packages can be conveniently selected by the operator of the labeling system.
Labeling systems in combination with weighing scales are used to automatically weigh and label random weight packaged items, perhaps most commonly packaged meat and produce in supermarkets. In such systems, weight, price-per-unit weight, total price and the like are printed onto labels which are applied to corresponding packages. One prior art system is shown in U.S. Pat. No. 4,561,921, issued Dec. 31, 1985, to Treiber and assigned to the same assignee as the present application.
Typically, packages are conveyed through such systems in a set orientation, for example, with one of the longer edges of each package being the leading edge through the system. Since all labels take the same path from the printer to the packages where they are applied, the labels are oriented the same for each of the packages. While it is possible to feed packages through the machine in other orientations to change the labeling format, the defined orientation is typically preferred since it provides the most stability and is less apt to cause operating problems with the system.
It is often desirable to be able to select the angular orientation of labels applied to packages. For example, the user of a labeling system may wish to arrange packages with either the longer or the shorter package edges being parallel to the front of a display case. If labels are applied in a single orientation by a labeling system, the arrangement of packages in a display case is effectively fixed since it is undesirable to have packages oriented such that the information on the labels runs other than upright and horizontally. Some newer display cases have multiple elevations and may be used most efficiently only by selecting label orientations dependent upon where in the case an item is to be displayed.
To overcome these problems, a number of arrangements have been developed in the prior art for controlling the orientation of labels relative to the packages to which they are applied. In U.S. Pat. No. 4,124,436, a label is delivered to an applicator head which takes the form of a vacuum cup. The applicator head engages the label by means of vacuum delivered to the head and is then lowered to press the label onto the surface of a package. If a label is to be applied to a package in a different angular orientation, the applicator head is rotated by means of a cam arrangement, with the amount of rotation being determined by the positioning of a cam follower pin within an elongated cam.
U.S. Pat. No. 3,616,094, discloses another arrangement for altering the angular orientation of labels applied to packages. A vacuum pickup tube, which is rotated through 180.degree. to pick up a label from a printing machine and move the label to a transfer position, includes a pickup nozzle mounted for rotary motion at the outer end of the pickup tube, with the pickup nozzle being rotated by means of one of a variety of cam and cam follower arrangements.
While the prior art arrangements do serve to rotate the applicator head and the pickup nozzle of the cited patents, respectively, they tend to be structurally complicated, hence, increasing the expense of a label applier incorporating such structure, while at the same time reducing its reliability.
Accordingly, it is apparent that there is a need for a label applicator which is inexpensive, simple in construction and reliable which permits easy operator selection of the angular orientation of labels applied to packages.